SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fb250f8835380dc3a278bdf533a07213246c54ff1ec96b9720a701165ab4ba02' 
  AND token = 'DUV+5W6DwZdaCW6sWHlg5Q0gjG3SO3GyyPL9NWOquMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}